str/bytes strictness.
diff --git a/Lib/test/test_genericpath.py b/Lib/test/test_genericpath.py
index 0c793ab..d912714 100644
--- a/Lib/test/test_genericpath.py
+++ b/Lib/test/test_genericpath.py
@@ -29,7 +29,7 @@
     def test_getsize(self):
         f = open(test_support.TESTFN, "wb")
         try:
-            f.write("foo")
+            f.write(b"foo")
             f.close()
             self.assertEqual(genericpath.getsize(test_support.TESTFN), 3)
         finally:
@@ -40,10 +40,10 @@
     def test_time(self):
         f = open(test_support.TESTFN, "wb")
         try:
-            f.write("foo")
+            f.write(b"foo")
             f.close()
             f = open(test_support.TESTFN, "ab")
-            f.write("bar")
+            f.write(b"bar")
             f.close()
             f = open(test_support.TESTFN, "rb")
             d = f.read()
@@ -63,7 +63,7 @@
         self.assertIs(genericpath.exists(test_support.TESTFN), False)
         f = open(test_support.TESTFN, "wb")
         try:
-            f.write("foo")
+            f.write(b"foo")
             f.close()
             self.assertIs(genericpath.exists(test_support.TESTFN), True)
         finally:
@@ -80,7 +80,7 @@
         self.assertIs(genericpath.isdir(test_support.TESTFN), False)
         f = open(test_support.TESTFN, "wb")
         try:
-            f.write("foo")
+            f.write(b"foo")
             f.close()
             self.assertIs(genericpath.isdir(test_support.TESTFN), False)
             os.remove(test_support.TESTFN)
@@ -105,7 +105,7 @@
         self.assertIs(genericpath.isfile(test_support.TESTFN), False)
         f = open(test_support.TESTFN, "wb")
         try:
-            f.write("foo")
+            f.write(b"foo")
             f.close()
             self.assertIs(genericpath.isfile(test_support.TESTFN), True)
             os.remove(test_support.TESTFN)
@@ -129,7 +129,7 @@
         def test_samefile(self):
             f = open(test_support.TESTFN + "1", "wb")
             try:
-                f.write("foo")
+                f.write(b"foo")
                 f.close()
                 self.assertIs(
                     genericpath.samefile(
@@ -154,7 +154,7 @@
                     )
                     os.remove(test_support.TESTFN + "2")
                     f = open(test_support.TESTFN + "2", "wb")
-                    f.write("bar")
+                    f.write(b"bar")
                     f.close()
                     self.assertIs(
                         genericpath.samefile(